The present invention relates to a display tube or cathode-ray tube and, more particularly, to a fluorescent display tube constituting a pixel of a color display device.
A large-screen color display device having a large number of fluorescent display tubes of different colors has been used in a variety of practical applications.
FIG. 1 shows a screen surface of a conventional color display device of this type. The circles represent display surfaces of single-color fluorescent display tubes. Reference symbols R, G, and B denote red, green, and blue, respectively. Three each of red, green, and blue fluorescent display tubes, a total of nine tubes, are used to constitute a 3 (rows).times.3 (columns) matrix. A conventional color display device of this matrix arrangement has a low total resolution due to predetermined spaces between adjacent tubes. In addition, the numbers of parts and manufacturing steps are large, resulting in inconvenience.